Support is requested for a community wide experiment to critically assess the current state of the art in the prediction of protein structure from sequence (CASP). This is the fourth experiment in the series. Previous experiments were held in 1994, 1996 and 1998. Ninety-eight groups from 21 countries submitted a total of approximately 4000 predictions in the last experiment. The goal is to provide an in-depth and objective assessment of our current abilities, and to assess progress since the last experiment. Information about soon to be solved structures will be solicited from the experimental community, and predictions of the structures of those targets collected and assessed. The collection of predictions will begin in April 2000, and run through August. The meeting will take place at the Asilomar Conference Center in California in December 2000, after the predictions have been assessed. Information about the complete process will be provided at a web site. This proposal requests support for the organizational and meeting components of the experiment. All data processing will be handled at the Lawrence Livermore Prediction center, separately funded.